5.3 Sedimentary Rocks (pg. 144)



Vocabulary


Sediment: Tiny pieces of material that develop from different rocks, of living things.
Deposition: The process of sediment in the water that goes out by either wind or water.
Compaction: The procedure in which time compresses sediments together.
Cementation: The method in which crystallization takes place in dissolved minerals, and keeps pieces of sediment together.
Clastic Rock: A type of sedimentary rock that is created when tiny pieces of rock are compressed together.
Organic Rock: Created from the leftovers of plants/ animals are left and formed into big, thick layers.
Chemical Rock: Created from dissolved materials that have crystallized either by time, or as an experiment.

Outline


From Sediment to Rock

  • Sedimentary rocks form from pieces of other materials deposited by wind and water
Erosion
  • Destructive forces are always breaking/wearing away rocks

Deposition
  • Eventually erosion forces slow down and deposit the sediment
  • After sediment is deposited, compaction+cementation change it into a rock
  • Living things may turn into fossils in the rock
Compaction
  • First sediment is loose, then it gets pushed together by new sediment
    • This happens for years
    • Sometimes the sediment layers are visible
Cementation
  • Minerals in rock dissolve in water
    • This makes it like "glue," hardening the rock

Types of Sedimentary Rocks


Clastic Rocks

  • Some rocks of made only of other rocks
Shale
  • Forms from tiny clay pieces
  • Is so compact that no "glue" is needed
  • Splits evenly, kind of like cleavage
Sandstone
  • Sandstone is formed from pieces of sand
  • Sandstone has many small holes because it is so lo0osely packed
Conglomerate and Breccia
  • Sometimes clastic rocks have big and small rock sizes
  • Breccia are rocks with sharp edges
  • Conglomerate are rocks with rounded edges

Organic Rocks

  • Organic rocks form from the remains of plants and animals
Coal
  • Coal is created from swamp plants
  • The plants form layers;then take years to form coal
Limestone
  • Limestone forms from skeletons and hard shells

Chemical Rocks

  • Chemical rocks are formed when minerals crystallize
  • They can also be formed from solutions
  • This process creates many common rocks

Uses of Sedimentary Rocks

  • There are many uses of limestone
  • The white house is made of sandstone, and so is the Taj Mahal!

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